Recent Progress on the VAX-FASTBUS Interface at KEK

This paper describes the recent progress on the FASTBUS Processor Interface (FPI) for VAX-11. The efforts are mainly focused on the development of a new microcode, which can dramatically reduce the data-taking overhead. The microcode interprets a list describing the data-taking sequence, and formats user data buffer in the VAX memory. The data-taking sequence is invoked automatically upon trigger recognition, without an intervention of the VAX CPU.